1. Field of the Invention
The present invention relates to a strength member for vehicle use. More particularly, the present invention relates to an air-conditioning duct structure having an air-conditioning duct contained in the strength member for vehicle use.
2. Description of the Related Art
Inside an instrument panel arranged in a front portion of a passenger compartment, that is, in the periphery of a dash panel which divides the passenger compartment from an engine compartment, there is provided a reinforcing bar which functions as a structural member for supporting a steering shaft. This reinforcing bar extends in the width direction of a vehicle, and a wire harness is attached to an upper face of the reinforcing bar.
In this connection, an interior air-conditioning unit of an air-conditioner for vehicle use is usually arranged at the center of a front portion of the passenger compartment, in the vehicle width direction inside the instrument panel. An air-conditioned air flow, the temperature of which has been adjusted by the air-conditioner, is blown out from a center face outlet, which is arranged at the center of the instrument panel in the vehicle width direction, onto a passenger's face at centerside in the passenger compartment. At the same time, an air-conditioned air flow is blown out from right and left side face outlets which are arranged on both end sides of the instrument panel in the vehicle width direction onto a passenger's face at both end sides in the passenger compartment.
Therefore, it is necessary to provide an air-conditioning duct (side face duct) for guiding the air-conditioned air flow from the interior air-conditioning unit, which is located at the center of the instrument panel in the vehicle width direction, to the face outlets which are located at both end sides in the passenger compartment. In general, this air-conditioning duct is arranged inside the instrument panel in such a manner that the air-conditioning duct extends substantially in parallel with the reinforcing bar.
As a result, inside the instrument panel, it is necessary to provide a mounting space, which is exclusively used for mounting the air-conditioning duct, which is different from the space in which the reinforcing bar is arranged. Due to the foregoing, the mounting property of the air-conditioning duct on the vehicle is deteriorated. In order to solve the above problems, the following technique is conventionally proposed. As a structure in which the air-conditioning duct is contained in the reinforcing bar, there is provided a structure in which the same space is used for a mounting space of mounting the air-conditioning duct and a mounting space of mounting the reinforcing bar, by which the mounting property of the air-conditioning duct can be improved.
As described before, the reinforcing bar must support the steering shaft. Therefore, rigidity of the reinforcing bar containing the air-conditioning duct must be somewhat high. For the above reasons, it is common that the reinforcing bar is made of metal. However, when the entire reinforcing bar is made of metal, the weight of the air-conditioning duct is increased.